ok, I got my NV610 unpacked today and put the WD800 on top for a run through.
Keep in mind that I have been working closely with the WD for the past few weeks, trying to make it sound as much like my WA as possible and I am very satisfied with that effort. WD does NOT sound entirely like the WA, it definitely has its own voice, but still they are very close (IMO/ to my ears).
So ... I can say without hesitation that the WD800 sounds great with the NV610 (I guess, no big surprise). I feel like the WD actually sounds a bit better thru the NV610 than the Walkabout .. perhaps its just a bit better wattage match (NV610 is rated at 750w).
For reference, my set up is:
Bass (Lull M4V or Roscoe Beck IV) => EBS Multicomp (Multi band mode, light compression, unity gain) => VT Deluxe (clean B15 settings) => Amp/Cab.
Sound is huge (to be expected) and tight. The NV610 seems to show the effect of the WD's Damping control a bit more than my CN (ported) cabs do. The WD stayed clearer, cleaner than the WA (of course, with more clean power on tap) and so the cab sounded better to my ears. The WA drives the NV610 just fine, but in louder situations (where the that much cab is used more often) it would also get woolier than the WD (again .. all that additional clean headroom/power coming into play).
I liked the sound of the WD+NV610 so much, that I believe I will take my NV610 off the TB classifieds. I was thinking about going with an NV212 for a smaller footprint, but now ... not so much